public class Demo3 {
    public static void main(String[] args) {
        StringBuffer sbu=new StringBuffer("abc");
        //append是追加，把下面的字符串追加到最初的abc后面
        System.out.println(sbu.append("cdef"));
        //在字符串1后插入zzz
        System.out.println(sbu.insert(1,"zzz"));
        //reverse反转，倒序
        System.out.println(sbu.reverse());
    }
}
